As documents have become more sophisticated, so have the techniques by which document features, or attributes, may be detected or authenticated. Even in the case of simple or traditional documents, advances have been made in the field of document feature detection or authentication. For example, acoustic technology may be suitable for detecting or analyzing certain features of a document. However, current acoustic techniques for detecting document features may suffer from poor signal-to-noise ratios, undesirable acoustic signal reflection, low resolution, or other issues.